Long-Acting Injectable Cabotegravir Use and Persistence Over 2 Years.

Importance: Long-acting injectable (LAI) pre-exposure prophylaxis (PrEP) has superior efficacy vs oral PrEP, and higher LAI-cabotegravir (CAB) persistence may optimize its HIV prevention impact. Objective: To characterize individuals using LAI-CAB compared with oral PrEP, to describe changes in national LAI-CAB vs oral PrEP use over time, and to examine longitudinal persistence among LAI-CAB users. Design, Setting, and Participants: This retrospective cohort study used pharmacy and medical claims from a database that covered a majority of all claims in the US from 2022 to 2024. Participants included persons with 1 or more claim for any PrEP drugs (oral or injectable). Exposure: PrEP use during the study period. Main Outcomes and Measures: Study outcomes were LAI-CAB use and persistence in care. LAI-CAB use was defined as at least 1 claim, and LAI-CAB yearly persistence was defined as at least 2 LAI-CAB claims for each of 2 biannual periods. Yearly persistence in any type of PrEP (PrEP persistence) was defined as at least 2 claims for PrEP medications (oral or injectable) for each of 2 biannual periods among LAI-CAB users. Multivariable logistic regression models were used to assess variables associated with LAI-CAB use compared with oral PrEP. Results: From 2022 to 2024, there were 24 194 LAI-CAB users, representing 3% of all 781 040 PrEP users. LAI-CAB users were young (mean [SD] age, 37.1 [11.4] years) and predominantly male (20 642 users [85%]); 656 (3%) were Asian, 4531 (19%) were Black, 4380 (19%) were Hispanic, 13 696 (58%) were White, and 414 (2%) were of other races and ethnicities. Most had commercial insurance (16 334 users [68%]) and had no copayment (13 507 users [82%]). LAI-CAB users were more likely than oral PrEP users to be covered by Medicaid (6256 of 24 194 users [26%] vs 108 589 of 770 833 users [14%]). In the most recent evaluated period (July to December 2024), LAI-CAB accounted for 4% (16 557 of 390 816 users) of PrEP users. Among users with sufficient data, LAI-CAB persistence was 50% (6020 of 12 118 users) at 1 year and 23% (785 of 3381 users) at 2 years. Overall PrEP persistence among LAI-CAB users, including transitions to oral PrEP, was 57% (6879 of 12 118 users) at 1 year and 30% (1019 of 3381 users) at 2 years. A greater proportion of female users initiated LAI-CAB (3551 users [15%]) than oral PrEP (83 274 users [11%]), but 2-year LAI-CAB persistence was lower among female users (61 users [13%]) than among male users (724 users [25%]). Conclusions and Relevance: In this national prescription claims cohort study, LAI-CAB use was a small share of overall PrEP use from 2022 to 2024. Approximately one-half of users were persistent in LAI-CAB or in PrEP at year 1, declining to about one-quarter and one-third, respectively, by year 2. The implementation of more effective new PrEP modalities alone is unlikely to substantially alter PrEP use in the US. Instead, structural supports and behavioral interventions are needed to facilitate scale-up of new, highly efficacious modalities.